The art of packaging deals with many problems depending on what is to be packaged and what is to be accomplished by the packaging. Usually the dominant factor in creating a package is to protect objects from damage during transportation. Other packages provide protection to handlers as would be the case in shipping razor blades, explosives, acids, and the like. In addition, packages may provide economy of shipping space, exclusion of dirt, ease of handling, attractive displays, identification of enclosed materials, shipping instructions, et catera, in many combinations depending on the requirements of the situation.
The packaging of modern sleeve bearings has very special requirements. These bearings in general comprise a cylindrical sleeve that is made up of two mating semicylindrical half sleeves placed end to end so that they accurately and closely encompass a round shaft within a bore so that the shaft is supported uniformly but is allowed to rotate freely on a thin intervening film of oil.
These bearing halves are made from shaped bi-metal sheets. The inside surface, which is next to the rotating shaft, is a comparatively soft bearing material such as babbitt metal or aluminum alloy, while the outer surface that mates with the bore is steel.
When parts such as these are transported it is absolutely necessary that the sharp steel end of one part does not mar or displace the smooth finish of the comparatively soft inner surface of the mating part.
This will occur if there is any movement such as oscillation, between the hard surface and the soft surface when in contact under pressure. Any such surface displacement is likely to destroy the intervening oil film referred to earlier and result in metal to metal contact between bearing and shaft. This in turn will cause premature failure in a bearing installation.
Consequently, in the past, semicylindrical sleeve bearings have been shipped in pairs in individual boxes with a separation of paper strip or the like positioned between bearing shells to prevent marring. Examples of such an arrangement are shown as in U.S. Pat. No. 3,307,685 to White, assigned to the assignor of the subject invention. U.S. Pat. No. 3,337,037 to Thill et al, also assigned to the assignor of the subject invention shows a similar invention wherein there is taught the use of a tab integral with the surrounding box as the separating member. In either case, however, a thin partition of some relatively soft material, such as paperboard, separates the enclosed parts from each other so that the sharp steel end of one half-bearing, or bearing shell, does not come in contact with the critical inner surface of the other half-bearing. If this were not done, one part could destroy the soft surface of the other part during shipment in the loosely confining package. The result would be a product that would be useless when it arrived in the hands of the consumer.
Such prior art packaging arrangements as above referred to are effective but costly in waste packaging material, waste shipping space, and inconvenience. It is these problems to which the present invention is addressed.